Megacities are cities or major urban areas with populations over 10 million inhabitants. Most megacities are commonly located in developing nations and rapidly emerging markets. These cities will continue to expand both in population and area growth.
Thirty-one megacities around the world represent almost 15% of the global GDP and are expected to increase to 20% of the global GDP in the next 10 years.
Population densities in emerging markets like Mumbai can be as high as 20,000 inhabitants per square kilometer. This density is more than double than that of London or Manhattan. In these cities, development is rapid which places stress on existing transportation infrastructure.